Fabricating structures impregnated with mixtures of vinylic resins and acryloxyalkylsilanes

ABSTRACT

METHOD OF MAKING MOLDED ARTICLES, PARTICULARLY OF FIBROUS GLASS, COMPRISING IMPREGNATING A SUBSTRATE WITH A MIXTURE OF A CURABLE VINYLIC RESIN AND AN ACRYLOXYALKYLSILANE AND SUBSEQUENTLY CURING TO FORM A CONSOLIDATED ARTICLE.

United States Patent Office 3,567,497 Patented Mar. 2, 1971 U.S. Cl.117-126 3 Claims ABSTRACT OF THE DISCLOSURE Method of making moldedarticles, particularly of fibrous glass, comprising impregnating asubstrate with a mixture of a curable vinylic resin and anacryloxyalkylsilane and subsequently curing to form a consolidatedarticle.

This application is a continuation-in-part of applicants copendingapplication Ser. No. 288,525, now U.S. Pat. 3,398,210, filed June 17,1963, which was a continuationin-part of applicants then copendingapplication Ser. No. 111,146, filed May 19, 1961, now abandoned, whichin turn was a continuation-in-part of their application Ser. No. 87,101,filed Feb. 6, 1961, now abandoned.

It is the primary object of this invention to provide improved moldedarticles of superior strength, particularly those made from resinscontaining aliphatic unsaturation and siliceous base members. Anotherobject is to provide novel combinations of the above silanes and vinylicresins 1 Which form superior molded articles. Other objects andadvantages will be apparent from the following descrip tion.

This invention relates to composite articles comprising (1) a basemember on the surface of which is a hydrolyzate of a compound of theformula in which R is a methyl radical or a hydrogen atom; R is adivalent group composed of carbon, hydrogen, and oxygen, the latterbeing in a configuration selected from the group consisting of etherlinkages and hydroxyl groups, in R the ratio of carbon atoms to oxygenatoms being not greater than 3 to 1 and R being attached to both the COand the R" groups through CO linkages; a has a value of 0 or 1; R" is analkylene radical of from 1 to 4 carbon atoms and X is a monovalenthydrolyzable group and (2) a cured vinylic resin.

For the purpose of this invention, R can be either hydrogen or a methylradical, thus it is obvious that the term acryloxy as employed hereinincludes methacryloxy compounds.

The silanes employed in this invention are of two types; namely, thoseof the formula CH =CRCOORSiX and those of the formula CH =CRCOOR'-R"SiXIt is believed that the beneficial characteristics of the silanes ofthis invention reside in the acryloxy group at one end and thetrifunctional silicon atom at the other. Thus, the purpose of R and R"is to provide stable bridges connecting the acryloxy group to thesilicon atom.

For the purpose of this invention R" is any alkylene radical of from 1to 4 carbon atoms such as methylene, ethylene, propylene, butylene andisobutylene.

The term vinylic resin as employed herein means resins which arepolymerizable via aliphatic 0:0 groups,

For the purpose of this invention R is an oxygenated radical in whichthe carbon oxygen ratio is not greater than 3 to 1. This is for thepurposeof maintaining the water solubility of the silane hydrolyzates aswill hereinafter be discussed. Thus, it can be seen that R can be anether radical such as (-OH2OH2O CHzCHOHzO OH2CH20-) OH (ICHzOHM and(-CH2C CH20) CHzOH For the purpose of this invention X can be anymonovalent hydrolyzable group. The term hydrolyzable group as employedherein means that the X group reacts with water under the normalconditions for hydrolyzing silanes. Thus X can be, for example, anyhalogen such as chlorine, bromine, iodine or fluorine, any groupcontaining a silicon nitrogen bond such as Me N, or Et N; any monovalenthydrocarbonoxy group such as methoxy, ethoxy, butoxy, isopropoxy, CH CHOH, or radicals of the formula (CH CH O) Y where Y is an aliphatichydrocarbon radical of 1 to 4 carbon atoms, phenoxy, cresyloxy and anyacyloxy group such as acetoxy, formyloxy, propionoxy; groups containingthe silicon-oxygen-nitrogen bond such as Me C=NO and Et C=NO and anysulphate group such as i i i no s 0-, M60 s 0- and 0- 0- It should alsobe understood that hydrocarbon portions of X can be substituted withother radicals to give, for example, CF CF O, CF COO-, Me NCH CH O,

and

Aqueous solutions of the hydrolyzates of the above silanes will often bethe most commercially desirable form in which to use these products andthe use of aqueous solutions to treat the base member is accordingly animportant modification of the invention. The precise molecularconfiguration of the organosilicon compound in these aqueous solutionsis not determinable. However, it is apparent that they represent highlyhydroxylated silanols and siloxanols. When these aqueous solutions areprepared from silanes where the HX by-product is a neutral compound, thewater solutions can be prepared by merely mixing the silane with water.However, in those cases Where HX produces a strongly acidic or astrongly basic solution it is desirable to buffer the solution so as tobring the pH close to the neutral point. This will render the aqueoussolution stable and hence more useable.

As stated above, one of the primary objects of this invention is toprovide composite articles of improved strength. This strength isbelieved to be due to improved adhesion between the base member orfiller andthe vinylic resin. These articles can be prepared in twogeneral ways. One way is to first treat the base member or filler withthe above silanes or their hydrolysis products, cure the silane andthereafter apply the resin to the treated base. member. An alternativemethod is to first add the silane to the vinylic resin and thereafterapply the mixture to thebase member or filler. a

In the latter method, best results are obtained when the silane isemployed in amount of from .05 to percent, preferably from .1 to 2percent by weight based on the weight of the vinylic resin. It isbelieved that the silanes can be first added to the resin because whenthe resin is mixed with the base member or filler, the silane tends tomigrate to thersurface of the filler and thereby acts as a couplingagent when the composite article is cured. 7 The first method supra formaking the articels involves treating (i.e., priming or coating) basemembers by;wetting at least a portion of the base member and with thedefined silanes, either as such or in hydrolyzed form. Ordinarily, thetreated surface will then be allowed to dry, and this can be done atordinary temperatures or can be accelerated by the use of elevatedtemperatures, reduced pressures, or both. The preferred method is to wetthe surface'with an aqueous solution of a hydrolyzate of the definedsilane. The optimum concentration of such a solution will depend uponthe nature of the surface to be treated, the effects desired in regardto altering the characteristics of that surface, and the particulartechnique employed in applying the solution to a particular surface;Organic solvents such as benzene, toluene, xylene, mineral spirits,methanol, ethanol, isopropanol, and chlorinated hydrocarbons can be usedto provide diluted solutions of the. silane, but cost and safety factorsmake aqueous solutions preferable, except in situations where water deesnot wet the material to be treated as well as an organic solvent does.Wetting agents or water-miscible organic solvents (such as the loweraliphatic alcohols, acetone, and tetrahydrofuran) can be used inconjunction with water to. improve the wetting characteristics of theaqueous solutions, and such modifiedsolutions' are intended to be withinthe scope of the term aqueous solution as used herein. n

The primary object in treating base members as above and of adding thesilanes or their partial hydrolyzates to the resin is to improve thebond obtainable between such membersand various polymerizable materialscontaining aliphatic unsaturation in the uncured state. Thus, the basemembers of greatest interest are those in which bonding of this type isof importance. Examples are' metallic and siliceous materials which areto be coated, impregnated, laminated, or the like, or to which othermaterials areto be adhered by means of an adhesive which is one of theaforesaid polymerizable materials. It is to be understood that the basemembers include materials of'small particle size, in which case bondingstrength is important because it affects the properties obtainable fromarticles in which the small particles are present as fillers and thelike. The base members also include material in the form of felted orwoven cloths and textiles, as well as all types of shaped solids,sheets, films, and fibers. In addition to siliceous and metallicmaterials, the base members can be composed of such diverse materials asthe metal oxides, organic plastics, organosiloxane resins and rubbers,natural and synthetic organic rubbers, and cellulosic products. At thepresent, the greatest improvements have been found in the treatment ofsiliceous materials.

The siliceous materials which are employed herein include all siliceousmaterials, but the invention is of particular interest with respect tothose which are to be employed with organic resins or rubbers havingaliphatic unsaturation in the uncured state, when used in such a waythat bonding between the siliceous material and the resin or rubber isdesired. The siliceous materials include mica, clay, and other silicateminerals such as asbestos, as well as vitreous enamel and ceramicsurfaces, quartz and the many varied forms of finely divided silica suchas diatomaceous earth, ground quartz, .silica aerogel, and fume silica.One of the most important siliceous materials to ,be treated inaccordance with this invention is glass, and this can be in sheets,fibers, or shaped forms thereof.

This invention isiinclusive of articles which comprise any base member,at least one surface of which or at least a portion of which has beentreated as above described. The articles of primary interest are thosecontaining treated siliceous materials. Such treated siliceous materialshave altered surface characteristics as evidenced by the improvedbonding obtained between the treated surface and any polymerizableorganic materials such as organic resins and rubbers containingaliphatic unsaturation in their uncured state. One of the most importantmanifestations of this improved bonding is found in the greatlyimprovedstrength of resinous and: rubbery'structures, such as molded orlaminated articles and the like, in which the treated siliceous materialis impregnated with the aforesaid polymerizable organic material.

The resinous and rubbery structures of this invention are produced byany of the conventional techniques for manufacturing such structures; Inessence, the siliceous material is contacted with the chosenpolymerizable ma-" terial, which can then'be polymerized to whateverdegree may be desired, ranging from partial polymerization to producepre-preg type materials to complete polymerization to produce finishedarticles. Molding compounds and the like can be produced by merelymixing the treated siliceous material into an appropriate resin orrubber.

Organic resins and rubbers containing aliphatic unsaturation in theuncured state are well known materials, and any of such materials can beused in practicing the present invention. The benefits of the inventionare particularly applicable to resins. The'term resin is used herein inthe conventional broader sense as being inclusive 3 of materials whichmay not be resinous in their uncured or monomeric state, so long as theyare used in a form which is polymerizable to a resinous state.

The preferred vinylic compounds used herein embrace any polymerizable orcopolymerizable compound containing the radical, Le. a vinylic typegroup in a terminal position in the molecule. The vinyl group orsubstituted vinyl group can be attached to any other substituents aslong as the resulting compound is one which is polymerizable. Thepolymerizable vinylic compounds are well known in the literature. It isto be understood, however, that the term polymerizable as employedherein, and as generally used in the art of organic polymers, does notnecessarily mean that the compound must be one which can polymerize withitself. In other words, it includes vinylic compounds which can onlycopolymerize with other vinylic compounds.

When the vinyl radical is attached to a benzene ring the reactant is, ofcourse, styrene, when it is attached to a cyanide radical the reactantwould be acrylonitrile. It can also be attached to carbon atoms whichare themselves attached to other substituents as in the methacrylates orallyl derivatives such as diallylphthalate, triallylcyanurate, and thelike, or the. vinylic radical may be attached to a mere hydrocarbonchain of some sort as in isoprene. Thus it can be seen that the termvinylic is used herein even though the vinyl group forms a mere portionof a larger radical in a manner such that the entire compound itselfwould or could be given a name which does not employ the prefix vinyl.

The vinylic compounds which can be employed in this invention fallwithin general types. These vinylic compounds can be defined as follows:

(1) Compounds of the formula CHFCHX where X is chlorine or one of theradicals -C H carbazolyl, COOR and -OR where R is a lower alkyl radical,e.g. of 1 to 8 inclusive carbon atoms. Thus the defined formularepresents the compounds vinyl chloride, styrene, divinylbenzene,dichlorostyrene, acrylonitrile, vinyl acetate, vinylpyridine,vinylcarbazole, alkylacrylates, and vinylalkyl ethers respectively.Preferably the R radicals are methyl or ethyl radicals.

(2) Compounds of the formula CI-I CYZ where Y and Z are either C1 or CHradicals, or where Y and Z are H or CH This formula represents thecompounds vinylidene chloride, isobutylene, propylene, ethylene andisopropenyl chloride.

(3) The lower alkyl methacrylates, particularly the methyl and ethylmethacrylates.

(4) Compounds of the formula CH CQCH CH where Q represents H or Cl atomsor the CH radical. This formula represents the compounds butadiene,chloroprene, and isoprene.

(5) Linear unsaturated polyesters.

It will be obvious that because of volatility or other handling problemsmany of the above described vinylic compounds are not ordinarily appliedin their monomeric state to base members when coating, impregnating,laminating, or molding such materials to prepare fabricated formsthereof. Where use of the vinylic compounds as such is not feasible forsuch reasons, or is not the ordinary practice, obviously the partiallypolymerized or partially copolymerized forms of the vinylic compoundswill be employed. It is just as obvious that the completely polymerizedforms of such polymers and copolymers would not be used, for they mustbe applied to the treated base member when they are still soluble in acarrier solvent or still liquid or fusible and hence operative ascoating, impregnating, laminating, or molding resins or rubbers. Inother words, the polymers or copolymers will be contacted with thetreated material when they still retain at least some of the residualaliphatic unsaturation upon which they rely for further polymerizationtherefore merely represents conventional coating, impregnating,laminating, or molding practices.

Resinous or rubbery polymers and copolymers of the above describedvinylic compounds are well known materials. Those of greatest interesthere are styrene, the acrylic, methacrylic, and polyester resins, andbutadienestyrene copolymers. It is to be understood that the vinyliccompounds above have been grouped into general types merely forconvenience in describing them. The copolymers useful herein can containdifferent polymeric units from any one general type or from two or moredifferent types, and, as is Well known, innumerable combinations ofthese various units are possible.

The treated materials of this invention can also be advantageouslycoated with or incorporated into natural polyolefinic rubber articles,as, for example, these prepared from Hevea brazilzensis, gutta balata,and gutta percha rubbers. Other types of resinous or rubbery materialswhich can be employed are organosiloxane rubbers and resins whichcontain at least some silicon atoms to which are attached unsaturatedaliphatic radicals (particularly vinyl or allyl radicals), and resinswhich are copolymers of organosiloxane units and units derived from theabove described vinylic compounds, so long as said copolymers retainsome residual aliphatic unsaturation. Organosiloxane rubbers and resinsof the described type have been amply described in the literature.

An outstanding example of the benefits obtainable from treatingsiliceous material in accordance with this invention is found in thepreparation of laminates and the like from treated glass fiber andpolyester resins. The improved bonding between the glass and the resinresults in articles having greatly improved fiexural and compressivestrength, and greatly improved retention of such strength when thearticles are exposed to water. This improvement in the properties ofarticles fabricated from polyester resins is sufiicient to upgrade thisrelatively inexpensive type of resin so that it has properties equal toor better than those obtainable from the relatively expensive epoxyresins.

The unsaturated polyester resins are a Well known class of materials. Ingeneral, they are the reaction products of alpha-beta ethylenicallyunsaturated dicarboxylic acids of anhydrides thereof with at least onepolyhydric alcohol (ordinarily a dihydric alcohol, i.e., a glycol).Typical acids which can be employed in producing such resins includemaleic, fumaric, itaconic, citraconic, mesaconic and aconic acids, andmaleic and citraconic anhydrides. Examples of suitable polyhydricalcohols include ethylene glycol, propylene glycol, neopentalene glycol,and diethylene glycol (i.e., 2,2-dihydroxyethyl ether). Higher boilingalcohols which are sometimes used in place of or in conjunction withthese glycols include compounds such as 2,2-bis-( p-hydroxyethoxyphenyl)propane; 2,2-bisp-hydroxyethoxyethoxyphenyl) propane; 2,2-bis-(p-hydroxypropoxyphenyl) propane, and 2,2-bis- (p-hydroxyethoxybiphenyl)propane.

As is well known, the dicarboxylic acids listed above can be partiallyreplaced in the polyester formulation by other dibasic acids,exemplified by adipic, succinic, sebacic, phthalic, isophthalic,terephthalic, and tetrachlorophthalic acids and anhydrides, any of whichare typically employed in amounts up to 3 moles per mole of thealphabeta unsaturated dibasic acid. Another typical modification of thepolyester resins which can be employed herein is the acid half-esterreaction product of at least one polyhydric alcohol ester of anhydroxylated unsaturated fatty acid (such as castor oil) with theaforesaid unsaturated dicarboxylic acids or anhydrides. Esters of, forexample, ricinoleic acid and ethylene or propylene glycol or glycerineand the like can of course be used to replace part or all of the castoroil in the latter modification.

The preferred polyester resins can be defined as comprising anesterification product of an alpha-ethylenic, alpha, beta-dicarboxylicacid with a glycol, said product being an advanced linear polyestercontaining unesterified carboxyl groups and preferably having an acidnumber of from 5 to 100. As is well known, the linear polyester isordinarily employed in admixture with a liquid monomeric unsaturatedpolymerizable compound, and hence the polyester should be miscible withand copolymerizable with said monomeric compound to yield a solidresinous material. Typical formulations of such mixtures range from 50to percent by weight of the polyester, and from 20 to 50 percent of theliquid monomeric compound. The liquid monomeric unsaturated compoundshave the group C=C in their molecular structure, and are exemplified bycompounds such as styrene, vinyl toluene, alpha-methylstyrene,divinylbenzene, 2,4-dichlorostyrene, vinyl acetate, methyl methacrylate,ethyl acrylate, diallyl phthalate, diallyl succinate, diallyl maleate,acrylonitrile, methylvinyl ketone, diallyl ether, methallyl alcohol,allyl crotonate, 1,3 chloroprene, butyl methacrylate, allyl acrylate,and triallyl cyanurate. Mixtures of two or more of these monomers canalso be used.

The term polyester resin as used herein is intended to include themixture of the linear polyester with the liquid monomeric unsaturatedpolymerizable compound as described above. The term also includes thepolyester and the aforesaid mixture as conventionally used inconjunction with a polymerization catalyst and as used with othertypical additives in such systems, as, for example, polymerizationinhibitors or accelerators.

The polymerization catalysts employed in polyester resin systems arewell known, and can be generally defined as vinyl addition typepolymerization catalysts. Any organic peroxidewhich will function as afree radical type polymerization initiator is operable. Examples includethe acyl peroxides, e.g., the benzoyl-, para-chlorobenzoyl-, 2,4dichlorobenzoyl-, and lauroyl peroxides and the like; hydroperoxidessuch as the t-butyl-, cumene-, and para-methane hydroperoxides; peroxyesters, e.g., di-t-butyl diperoxyphthalate, t-butyl peroxyacetate, etc.;alkyl peroxides such as di-t-butyl peroxide and dibenzyl peroxide;ketone peroxides such as methylethyl ketone peroxide and cyclohexanoneperoxide; and other organic per compounds such as t-butyl perbenzoateand di-tbutyl diperphthalate. The catalysts are ordinarily employed inamounts ranging from about 0.1 percent to 2 percent by weight, based onthe weight of the polyester resin formulation. Typical accelerators usedin these systems include the well known driers such as cobaltnaphthenate; azomethine compounds, and polyamino compounds having atleast one terminal primary amino group, along with the aldehyde reactionproducts of the latter. Such accelerators are commonly used in amountsof from about 0.01 percent to 2 percent by weight based on the weight ofthe polyester resin formulation. Typical polymerization inhibitorsemployed to prevent unwanted premature polymerization in the system aresubstituted phenols and aromatic amines as, for example, hydroquinone,resorcinol, sym. alpha, beta-naphthyl diamine, and p-phenylene diamine,and amounts of fromabout 0.01 percent to 0.1 percent are generallysufficient.

The catalysts, accelerators, and inhibitors described above with respectto the polyester resin systems are also often employed with many of theothre polymerizable organic materials containing aliphatic unsaturationin the uncured state. Of course, many other catalysts are known for theresinous and rubbery polymers and copolymers which have been describedabove, and the present invention contemplates the use of any of suchcatalysts, for the invention does not lie in the selection of anyparticular polymer-catalyst system.

After the polymerizable organic material is applied to the treated basemember or added to the resin and the base member is then contacted withthe mixture, the resulting composite mass is subjected to vinylpolymerizing conditions to bring about the degree of curing desired inthat mass. The vinyl polymerizing conditions include the use of heatalone, use of ionizing radiation, and use of the various vinylpolymerization catalysts. In addition to the organic peroxides describedabove, typical catalysts include inorganic peroxides such as hydrogenperoxide and sodium peroxide, ozone, ammonium persulfate, potassiumpermanganate, and other free radical generators such as the azocompounds containing tertiary carbon atoms attached to each nitrogenatom of the azo linkage and in which the remaining valences of thetertiary carbon are satisfied by nitrile radicals, carboxyalkylradicals, cycloalkylene radicals, alkyl radicals,

and radicals of the formula YOOC where Y is an alkyl radical. Thecompound u,a'azodiisobutyronitrile is an example of a preferred type ofazo compound.

No meaningful range of curing times and temperatures can be set forthfor the many systems of polymerizable materials and catalystscontemplated here, for innumerable optimum conditions exist, dependingupon the system used. Appropriate curing conditions for these varioussystems are well known, and range from room temperature below thedecomposition point of the resin or rubber employed.

The alkoxysilanes employed in this invention can be prepared by severalbasic methods. One of thse involves compounds in which R" has from 2 to4 carbon atoms.

8 This method involves the addition reaction of a compound of theformula where R" is an unsaturated radical such as vinyl, allyl,methallyl or butenyl, with HSiX These addition reactions are bestcarried out in the presence of platinum catalyst such as platinumdeposited on alumina and chloroplatinic acid. The reaction temperaturesare in the region of 50 to 115 C. The platinum is best employed in aconcentration of about 1 10 moles per mole of unsaturated reactant.

Specific examples illustrating the above reactions are:

CHFC M6 COO (CHzCHg 4 CH CMB=CH +HSi OAC) CH C (Me 4 OH CH Me) CH SiOAc) 3 CH =CHCOOCH=CH +HSi OCH OH OMe) CH CHCOO-CH OH Si OCH CH OMe 3The symbols Me, Et, and Ac have been used above and will be usedthroughout this specification as representative of methyl, ethyl, andacetyl radicals respectfully. If desired, one can carry out the additionreaction employing HSiX and thereafter exchange the X radicals in theresulting silanes for other X radicals. Thus, for example, thechlorosilane shown above can be reacted with methanol to produce thecorresponding trimethoxysilane. Alternatively, the chlorosilane can bereacted with the salt of an acid such as sodium acetate or sodiumbenzoate to prepare the corresponding triacetoxy or tribenzoyloxysilane.Again the triethoxysilane shown above can be refluxed with a highboiling alcohol such as betamethoxyethanol to produce thetris-(beta-rnethoxyethoxy)-silane. In such an interchange ethanol wouldbe evolved.

A second general method of preparing the silanes employed in thisinvention is to first prepare an ep0xysilane of the formula HzCHIV'SiX;

These compounds are prepared by reacting unsaturated epoxides of theformula with silanes of the formula HSiX In carrying out this reaction,of course, X must be a radical which is unreactive toward the epoxidegroup. This includes alkoxy and acyloxy silanes, in which the alkoxy andacyloxy groups are free of active hydrogen. The resulting additionproduct is then reacted with an hydroxy ester of acrylic or methacrylicacid such as, for example, beta-hydroxyethoxymethacrylate. This reactionis carried out in the standard method for reacting alcohols withepoxides and is generally done by employing catalysts such as stannicchloride and temperatures in the range of 50 to C. An illustrativereaction is as follows:

In carrying out any of the above reactions, it is desirable to employpolymerization inhibitors such as copper acetate and hydroquinone toprevent polymerization of the silane product by way of the acrylatedouble bond.

The third general method for preparing the silanes employed in thisinvention is especially applicable Where R" is a methylene radical.However, it can be used where R" contains more than one carbon. Thisreaction entails reacting a tertiary amine salt of acrylic ormethacrylic acid (the organic radicals attached directly to nitrogen insaid salt being alkyl radicals of from 1 to 4 inclusive carbon atoms)with a chloroalkylsilane of the formula ClCH (CH Si(OR) where x is 0, 1,2, or 3. It will be seen that the products of this invention wherein R"is methylene will be produced when x in the above reactant is 0.Triethylamine is the preferred amine to form the reactant salt, and thesalt as such does not necessarily have to be isolated. In other words,the amine and the chosen acid can be merely mixed, and thechloroalkylsilane added to the mixture in approximately stoichiometricquantities. Preferably the reaction is carried out in the presence of aninert organic solvent such as benzene, toluene, xylene, or cyclohexane,at reaction temperatures of about 100 to 150 C. It is also best to carryout the reaction in the presence of one or more polymerizationinhibitors for acrylic or methacrylic acid, such as hydroquinone andN,N-diphenylene diamine. The reaction proceeds with the formation of thedesired product CH CRCOOR',,-R"Si(OR') and the precipitation of theby-product tertiary'amine hydrochloride. The chloroalkylsilane reactantscan be prepared, for example, by the reaction of vinyl-, allyl-, orbutenyl chloride with HSi(OR) using chloroplatinic acid as the catalyst,or by the same reaction with HSCl followed by alkoxylation oracyloxylation of the chlorosilane adduct. The reactants of the formulaClCH Si(OR) can be prepared by the chlorination of MeSiCl to produceClCH SiCl followed by alkoxylation or acyloxylation of the latter.

In the preparation of aqueous solutions from the above organosilanes,the hydrolysis water is best employed at a pH from 3 to 7 inclusive. Ata pH of 7, however, a rather long time is required to reach the watersoluble hydrolyzate stage, thus, a pH of from 3.5 to is preferred. Oncethe water soluble state is reached, it is immaterial whether any waterused for further dilution is on the acid side. Preferably the hydrolysiswater is made mildly acidic with a water soluble carboxylic acid such asacetic or propanoic acids. This aids in the hydrolysis of the (OR)groups, but does not bring about the more rapid and more completecondensation of silanol groups which will take place if a base or astronger acid is used to expedite the hydrolysis. Such condensation isto be avoided because the resulting siloxanes and siloxanols will geland precipitate out of the aqueous solution, i.e., the shelf life of thesolution will be poor. In general, the best results are obtained bymixing the defined organosilanes with water which contains about 0.1percent by weight of acetic acid. If desired, Water miscible solventscan be added to the aqueous solution to improve its shelf life andwetting characteristics. The acetoxysilanes of this invention will, ofcourse, provide their own acid upon contact with water.

In case one uses halosilanes or other silanes producing strong acidsupon hydrolysis, it is necessary to butter the hydrolysis solution toprevent gelation of the hydrolyzate. This is best done by adding adilute solution of the silane in a water soluble solvent such asacetone, to dilute aqueous ammonia.

Base members can be treated with the organosilanes of this invention, orwith solutions of such inorganic solvents, and in this case the water onthe base member itself and/or atmospheric moisture or treatment withsteam or other sources of water (with acidic or basic hydrolysiscatalysts added if desired) can be relied upon to bring about hydrolysisof the organosilane. In such a case, the treated base member is thenpreferably heated to expedite the condensation of the hydrolyzate toproduce a permanent, insoluble sizing or finish on the base member.Comparable results can be obtained by permitting the treated base memberto stand for longer periods of time-at room temperature. The fullycondensed siloxane polymer which is ultimately formed on the base memberconsists essentially of siloxane units of the formula CH =CRCOOR,,RSiO

Another technique for treating a base member is by hydrolyzing orpartially hydrolyzing the organosilanes with an amount of water whichprovides little or no excess over the theoretical amount necessary toform the Si(OH) compound (or which is insufficient for such completehydrolysis), dissolving the resulting hydrolyzate or partial hydrolyzatein an organic solvent, and applying the solvent solution to the basemember. This removes or reduces the need for any hydrolysis to takeplace on the base member itself. Condensation of the hydroly- Zate isthen allowed to take place by allowing the treated base member to standat room temperature, or is expedited at elevated temperatures, as in thepreviously discussed treatment.

The use of aqueous solutions of the hydrolyzates of the definedorganosilanes is generally preferred. The concentration of organosiliconhydrolyzate in the solution can vary over an extremely wide range, forexample, from 0.1 to percent, and optimum concentrations for treating.base members will depend upon the nature of the base member and uponthe use to be made of it, as well as upon the method of application.Even when a single type of base member is under consideration, theoptimum concentration varies with the method of application. In thetreatment of glass fiber, for example, the aqueous solutions are bestused at a concentration of 5 to 10 percent when applied to the glassfiber as it is drawn at speeds up to 10,000 feet per minute out of abushing in its manufacture. The typical method of application here is tokeep a roller, moving belt, or pad moistened with the treating solutionand to contact the fiber therewith as the fiber is drawn. Treating thefiber at this stage and at this concentration provides both lubricationand sufficient cohesiveness of the treated fibers to permit their beingtwisted into threads, strands, or roving. This eliminates the need forthe use of conventional organic lubricating and bonding agents, and atthe same time provides a glass filber having an enhanced ability to bondto polymerizable materials. In contrast, when woven glass fiber cloth isbeing treated, a concentration of only 0.25 to 1.5 percent is generallysufficient to produce the desired results, for the relatively longcontact time of the typical spraying or dipping operation permits agreater amount of the solution to be picked up. The concentrations ofthe aqueous solutions referred to above are in terms of the weightpercent of the unhydrolyzed monomeric organosilane used in thepreparation of the solution, based upon the weight of that solution.

In the treatment of glass cloth or other forms of glass fiber by any ofthe above techniques, it is preferable to operate in a manner such thatthe theoretical pick-up of organosilicon compound, calculated as rangesfrom about 0.1 to 0.75 percent by weight based on the weight of theglass. Any attempt to give comparable pick-up figures for base membersin general is meaningless, however, because of the vast variation in theratio of treated surface area to weight in the many diverse types ofbase members whose treatment is contemplated here. In general, thesiloxane coatings produced on base members in the treatment of thisinvention will be too thin to be visible, i.e., no obvious tangible filmwill be produced, and in fact the film can range down to that of amonomolecular layer. If desired, however, a thick, tangible layer can bebuilt up by using more concentrated forms of treating solutions or byrepeated applications, or by using partiallly polymerized hydrolyzates.

In the treatment of base members it is preferred that said members berelatively free of any surface contaminations such as oil, grease, ordirt. In the treatment of glass (OMe) groups.

fiber, it is preferred that the fiber be free of any organic lubricatingagents, bonding agents, or the like which may have been employed in itsmanufacture. Clean glass fiber, gglass cloth,aetc. are commerciallyavailable materials, an example being the heat-cleaned glass cloth whichis produced by literallly burning the organic agents off of the glass atelevated temperatures. i

The following examples are illustrative only. The symhols Me, 'Et, i-Pr,Bu and 'Ac have been used to represent methyl, ethyl, isopropyl, butyland acetyl radicals respectively. All parts and percentages mentionedare by weight. a I I EXAMPLE' 1 A mixture of 1,000 ml. toluene, 12 g2,5-diter'tiarybutyl hydroquinone, 61 g. (0.5 mole) HSi(OMe) and g. of asolution of H PtCl '6H O' in methylbenzoate (said solution containing 1percent by weight Pt) was heated to 105 C. and .a mixture of 427 g. (3.5moles) HSi(OMe) and 504 g. (4 moles) allylmethacryiate was added theretoover a period of about 1.5 hours. The exothermic reaction taking placeduring this addition maintained the temperature at about 105 C. Thereaction mass was heated for one hour at 110 to 112 C., cooled, and' 10g. hydroquinone and 5 g. 2,5 -ditertiarybutyl hydroquinone addedthereto. Volatiles were stripped off and the residuef was distilledthrough a 12-inch Vigreaux column. The desired product .cH ctMe)coo(cH,si(oMe was distilled Off at 100 c. to 116 o. at 5mm. Hg pressure.Redistillation of the product cuts throughthe Yigreaux column showed aboiling range of 94 to 96 C. at 1 mm. Hg p5 1.4305.

EXAMPLE 2 A m'tafture of 200 ml. toluene, 0.5 g. 2,5-ditertiarybutylhydroquinone, 12.2 g. HSi(OMe) and 0.6 g. of the 'H PtCl-6H O solutionof Example 1 was heated to 110 thereto. After stripping off volatiles,the residue'was distilled through the 12*inch Vigreaux column to givethe product CH =CHCOO(CH Si(OMe) boiling at 65 to 70 C. at 0.1 Hgpressure, n 1.4155.

. EXAMPLE 3 W Q When the compounds HSi(OEt) HSi(Oi-Pr) HSi(OAc) HSi(OCHCH OBu) or HSi(OH CH OMe) are substituted for HSi(Ol\ e) in thereactions of Examples 1 and 2, the products obtained correspond tothoseof said examples with (QEt) groups etc. attached to the siliconatom in, place of the EXAMPLE 4 When vinyl methacrylate is used in placeof allylmethacrylate inthe process of Example'l, the compound CHC(Me);COO(CH Si(OME) is produced.

EXAMPLE 5 MeSiCl wa's chlorinated to produce clCH Si fll The latter wasreacted with methanol to produce ClCH Si(OMe) When a solution of 1 moletriethylamine, 1 mole meth acrylic acid, 15 parts hydroquinone, 300parts xylene, and 0.9 mole ClCH Si(OMe) is heated at reflux for 16hours, filtration and distillation of the reaction mass yields theproduct CH =C(Me) COOCH Si(OMe) EXAMPLE 6 1 A mixture; of 1 part CH=CHCOO(CH Si(OME) and 20 parts 0.1 percent acetic acid in aqueoussolution was agitated slightly to form an homogeneous solution of theresulting hydroiyzate, then 179 parts water was added to form a 0.5percent solution based on the'original organosilane. Glass cloth havingthe commercial designation 112" (i.e., 181 style glass cloth which hadseen heat-cleaned) was dipped in the 0.5' percent solution. The glasscloth picked up about 65 percent of its weight of the solution,representing a pick-up of about 0.23 percent calculated as CH =CHCOO(CHSiO The cloth was allowed to dry at room temperature, and was thenheated 7 minutes at 230 F. n

A laminate was prepared containing 14 plies of the treated glass cloth(laid up with the warp threads rotated in alternate plies) impregnatedwith a polyester resin, the laminate being cured 30 minutes at 30 psi.and C. to form a ngolded sheet having a thickness of about mils andcontaining about 30 percent by weight of the cured polyester resin. Theresin employed was a solution of 70 parts linear polyester in 30 partsof styrene monomer, to which had been added 0.5 part benzoyl peroxidedissolved in about 7.5 parts styrene monomer. The linear "polyester inthis resin mixture was one prepared from phthalic acid and maleic acidin equimolar proportions reacted with propylene glycol, the 70 percentsolution of this polyester in styrene having an acid number of about 35.The flexural strength of this laminate was determined in accordance withthe US. Federal Specification L-P 406b-Method 1031, and compressivestrength was determined in accordance with Method 1021 of thatspecification. Flexural strength was also determined on a sample of thelaminate which had been boiled in water for 2 hours and'then wiped dry,this being a test which is recognized as roughly the equivalent pfstanding in water at room temperatilre for one month. Results from thelatter test will be referred to hereafter as the 2-hr. boil data. The2-hr. boil flexural strength times 100 divided by the strength of thelaminate as molded is the percent retention. The following results wereobtained on the laminate prepared above, the strengths being reported inp.s.i.:

Flexural strength 82,400 2-hr. boil 76,200 Percent retention 93Compressive strength 44,900

For purposes of comparison, a laminate was prepared in the same way fromthe same polyester resin but the glass cloth employed was not treatedwith theorganosilane. The test results were as follows:

Flexural strength 50 ,700

2-hr. boil 32,600 Percent retention LI 64 Compressive strength 29,600

EXAMPLE 7 i A mixture of l part CH =C(Me)COO(CH Co(OMe) and 20 parts 0.1percent acetic acid solution was agitated until homogeneous, thendiluted with179 parts additional 0.1 percent acetic acid. "A sample of112 heatcleaned glass'cloth was dipped in the solution, air-dried, andheated 7 minutesat 230 F. The treated glass cloth contained about 0.24percent of its own weight of the organosilicon coating, calculated asDifferent laminates were prepared from this treated cloth, as follows W(A) A laminate was prepared by'the same technique and from the samebenzoyl peroxide catalyzed polyester 13 resin system as in Example 6.Test data showed the following results:

The increase in strength after boiling the laminate for 2 hoursindicates that the laminate as molded was not quite fully cured, andfurther curing took place during the boiling which more than offset anyslight decrease in strength which may have been brought about byexposure to the water.

(B) A laminate was prepared by impregnating 14 alternated plies of thetreated glass cloth with the polyester resin described in Example 6. Inplace of the benzoyl peroxide catalyst, however, a system which wouldcure at room temperature was produced by adding to the resin a doublecatalyst consisting of suflicient cobalt octoate to provide 0.03 percentCo in the resin, and 0.5 percent methylethyl ketone peroxide. Theimpregnated glass cloth was molded at room temperature for 24 hoursunder an initial pressure of 30 p.s.i., with stops set in the mold. Thefinal laminate had a thickness of 123 mils. The laminate so produced wasremoved from the mold, given an after-cure in an oven at 140 F. for 6hours, and tested with the following results:

Flexural strength 96,000 2-hr. boil 86,300 Percent retention 90Compressive strength 65,000

(C) Another room-temperature cured laminated was prepared byimpregnating 14 alternated plies of the treated glass cloth with apolyester resin consisting of 75 percent of the linear polyesterdescribed in Example 6 and 25 percent methylmethacrylate, This resincontained 0.25 percent methylethyl ketone peroxide and 0.007 percent Coadded as cobalt octoate. The impregnated assembly was molded 24 hours atroom temperature as before, and then after-cured for 12 hours at 140 F.The laminate was 120 mils thick and had the following properties:

Flexural strength 97,100 2-hr. boil 85,500 Percent retention 88Compressive strength 61,400

Flexural strength 100,000 2-hr. boil 95,600 Percent retention 95.6

Compressive strength 43,700

For the purposes of comparison, another laminate was prepared in thesame way from the same resin, using glass gloth which had not beentreated with organosilicon compound, and this laminate had the followingproperties:

Flexural strength 15,200 2-hr. boil 14,400 Compressive strength 11,200

(E) A solution was prepared of 66.5 parts of a resinous copolymer havinga viscosity of about 3300 poises at 77 F. and being the reaction productof 4 moles butadiene and 1 mole styrene, in 66.5 parts of vinyl toluene,

and 3.65 parts dicumyl peroxide and 3.65 p'arts di-t-butyl peroxide wereadded thereto. A laminate was prepared by impregnating 14 alternatedplies of the treated glass cloth with this solution, and molding theassembly for 40 minutes at 175 C. and 30 psi. This laminate had thefollowing properties:

Flexural strength 49,300 2-hr. boil 47,400 Percent retention 96Compressive strength 21,000

For purposes of comparison, another laminate was prepared in the samemanner but using glass cloth which had not been treated with theorganosilicon compound. The test results were as follows.

Flexural strength 12,600 2-hr. boil 7,200

(F) A solution of 60 parts of a resinous copolymer having a viscosity of4600 poises at 77 F. and being a copolymer of butadiene and styrene in a4:1 molar ratio, 40 parts vinyltoluene, 2 parts dicumyl peroxide, and 2parts di-t-butyl peroxide was used to impregnate 14 alternated plies ofthe treated glass cloth. The assembly was molded at 30 psi. for 30minutes at 300 F. and 30 minutes at 320 F., then removed from the pressand post-cured 2 hours at 350 F. This laminate had a thickness of milsand had the following properties,

Flexural strength 54,600 2-hr. boil 55,200 Compressive strength 30,000

A laminate prepared in the same way from the same resin, but usinguntreated glass cloth, had a flexural strength of only 26,800; 2-hr.boil strength of 10,200; and a compressive strength of 9,600.

EXAMPLE 8 A mixture of 15 parts CH =C(Me) COO (CH 'Si(-OMe) and parts of0.1 percent acetic acid was agitated until a homogeneous solution of theresulting hydrolyzate was obtained, and the solution was then dilutedwith 1350 parts 0.1 percent acetic acid to provide a 1 percent solutionof the starting silane. Heat-cleaned 60-end glass fiber roving waspassed through the solution and then through a curing tower in which airwas circulated at 250 F., the speed of passage being such that theroving was heated for about 2.5 minutes. In this treatment the rovingshowed a pickup of about 0.45 percent of its weight of siloxane solids,calculated as CH =C(Me)C-OO(CH SiO The treated roving was wound inparallel fashion around a metal frame in a manner to provide about 2.72g. of glass per square inch. The assembly was impregnated with thepolyester resin system of Example 6, and press molded 30 minutes at 30p.s.i. and 100 C. The resulting laminate was cut away from the metalframe and cut into test specimens the length of which ran parallel tothe direction of the glass roving. Test results were as follows. (Notethat a longer exposure to boiling water was used.)

Flexural strength W 176,500 24-hr. boil 147,300 Percent retention 84 Incontrast, laminates prepared in the same way from heat-cleaned glassroving which had not been treated showed the following properties.

Flexural strength 130,000 24-hr. boil 57,100 Percent retention 44 Asanother comparison, an additional laminate was prepared in the same wayexcept that the glass fiber roving employed was a commercially treatedroving in which vinyl substituted silanes are used as the treatingagent.

15 This roving represents the best of the hitherto available rovingsinsofar as the preparation of polyester laminates is concerned. The testresults were as follows:

Flexural strength 150,000 24-hr. boil 93,500 Percent retention 62EXAMPLE 9' When CH C(Me)COO(CH Si(Oi--Pr) or the corresponding -Si(OAc)and -Si(OCH CH OMe) compounds or CHFC(Me)COOCH Si(OMe) or CHFCHCOO (CHSi OEt) 3 are used in place of the Si(OMe) compound in the treatmentdescribed in Example 7, and laminates then prepared as described in thatexample, comparable improvements in the strength of the laminates areobtained.

Laminates have been shown in the above examples because they illustrateso well the improvement in bond strength between a siliceous materialand a polymerizable unsaturated material which can be brought about bythis invention. It will be obvious that the improvement in bond strengthwill be equally important in many other usages, as, for example, intreating sheets of glass which will be used in sandwich structures suchas safety glass; in treating glass, ceramics, vitreous enamel surfacesand the like which are to be given protective or decorative coatings ofpaints, enamels, or varnishes containing unsaturated resins, in treatingglass fiber textiles which are to be colored by pigments dispersed inunsaturated resins such as the acrylic latex pigment bonding systemsconventionally used for that purpose; in treating silica, titania,alumina, iron oxide, and other metal oxide fillers, as well as mica,asbestos, chopped glass, etc. to improve the reinforcement effect ofsuch fillers in unsaturated resinous or rubbery articles; and in thetreatment of metal surfaces such as steel, iron, and aluminum to improvethe adhesion of protective and decorative coatings or of bodies ofunsaturated resins and rubbers thereto. The treatment of steel andaluminum with the aqueous solutions of hydrolyzates described inExamples 6 and 7 has been found to provide a surface against whichsilicone rubber (such as that containing dimethylsiloxane andmethylvinylsiloxane copolymer units) can be vulcanized to produce a bondto the metal which is stronger than the silicone rubber itself.

EXAMPLE 10 One mole of allylmethacrylate containing 1 percent by weighthydroquinone was mixed with 100 p.p.m. platinum added as chloroplatinicacid and the mixture was heated to 70 to 80 C. as one mole oftrichlorosilane was added. The product was heated one hour longer at 80C. then distilled to give CH C (Me) COO (CH SiCl boiling at 100 C. at 1mm. and having a density at 25 C. of 1.238.

This material was applied to 181 glass cloth and washed and dried togive a Weight pickup of .25 percent by weight of the glass. The primedglass cloth was laminated with the polyester resin as described inExample 6 and the cured laminate had the following properties:

Flexural strength 86,800

2-hr. boil 82,500

Percent retention 95 Compression strength 53,700

EXAMPLE 11 A mixture of 150 ml. of benzene, .15 mole of CH =C(Me) COO(CH SiCl and .45 mole of alpha-picoline was cooled to C. There was addedthereto a solution of .6 mole of acetoxime in 200 1111. Di benzene. Themixture was held at to 16 C. for one hour and then heated to 55 to 60 C.The product was cooled and filtered free of alpha-picolinehydrochloride. The solvent was then removed from the filtrate to givethe liquid compound This product was dissolved in water to give a .6percent by weight solution based on the weight of the correspondingsiloxane and the solution was then used to impregnate 181 glass clothand the resulting product laminated with the polyester resin asdescribed in Example 6. The cured laminates had the followingproperties:

Flexural strength 86,300

2-hr. boil 79,175

Percent retention 92 Compressive strength 47,700

EXAMPLE 12 g. of methylmethacrylate and g. of beta-(allyloxy)ethanolwere dissolved in g. of toluene and mixed with .5 g. of hydroquinone and2 g. of concentrated sulfur acid. The mixture was refluxed for 6 hoursas methanol was removed. The resulting ester was washed, dried, anddistilled.

66 g. of the ester was mixed with 61 g. of trimethoxysilane, 73 g. oftetrahydrofuran, 1 g. of phenyl-betanaphthyl amine, .5 g. ofhydroquinone and .10 g. of a one percent solution of chloroplatinic acidin alcohol. The mixture was warmed to 65 to 75 C. for two hours and thendistilled to give the product CH =C(Me)CO-OCH CH O (CH Si (OMe) havingthe following properties: B.P. to C. at 3 mm., d of 1.057 and 11 1.4365.

The product was dissolved in water as shown in Example 6, and applied to181 glass cloth as shown in that example. The resulting cloth waslaminated with the polyester resin as shown in Example 6 and the curedlaminates had the following properties:

Flexural strength 97,600

2-hr. boil 97,000

Percent retention 99 Compressive strength 54,600

EXAMPLE 13 13 g. of beta-hydroxyethylmethacrylate was dissolved in 13 g.of ethyleneglycol dimethylether. .01 g. of hydroquinone and 10 drops ofstannic chloride were added thereto and then 23.6 g. of

CEz CHCHZO (OHz)aSi(0Me)3 was added as the mixture was cooled on a waterbath held at 20 C. The mixture was then allowed to stand for one hourand the product was a water soluble fluid having the formula Thismaterial was applied to 181 glass cloth and laminated as shown inExample 6 and the resulting cured laminates had the followingproperties:

Flexural strength 84,200

2-hr. boil 77,000

Percent retention 91 Compressive strength 44,500

EXAMPLE 14 The procedure of Example 13 was repeated except that 14.4 g.of beta-hydroxypropylmethacrylate was employed. The resulting productwas a water soluble material having the formula OHz=C(Me) 0o ooI-IzomMeOCHzCHCHeO (CH2)sSi(OMe) This product was applied to glass and laminatedin accordadded as Pt on alumina the following products are obtained:

Ester Silane Product CH -o e 000 CH CH CH CH=CH2 HSi(NMe2)sGHQ-O(Me)OOO(OH2CH O)iuo(GH2)sSi(NMe2) onioiibboucgmdm canibmicnzcn=omHSi(0CH2C 2C1)s c1n=oHcoo ciniomtcanfiomitcnnasnocnzcnz CHFC (Me) 00 OCHzC (Me)=OHg 011.:0 (Me)COOCHiC (Me)=CHz HSi(OEt)a ance with theprocedure of Example 6 to give the following properties for the curedlaminates:

Flexural strength 84,600

2-hr. boil 81,200

Percent retention 96 Compressive strength 49,300

EXAMPLE The composition CH =C(Me)OC(CH Si(OMe) was added to thepolyester resin of Example 6 in the amounts shown below. Heat-cleaned181 glass cloth was impregnated with the mixture. The impregnated glasswas laminated and cured as shown in Example 6. The laminates had thefollowing properties:

One percent of CH =C(Me)COO(CH Si(OMe) was added to styrene monomer. Themixture was polymerized with benzoyl peroxide in contact with glass. Theresulting polymer adhered tenaciously to the glass giving adhesionequivalent to that obtained with epoxy resins.

EXAMPLE 17 .5 percent by Weight of CH C(Me)COO(CH Si(OMe) was added to acommercial methylmethacrylate lacquer. The mixture was applied to glasspanels and the panels were air dried 24 hours and then heated 1 hour at250 F. The adhesion was excellent. The panels were then submerged inwater at 25 C. for one hour. The adhesion was still excellent. Bycontrast when the glass was coated with the methacrylate lacquer alone,cured as above and submerged in water one hour at 25 C. the adhesion waspoor.

EXAMPLE 18 When the following acrylic esters are reacted with thefollowing silanes in the presence of 100 p.p.m. platinum CHFC (Me)COOCH2CH(M8) CHzSi (O OCC EXAMPLE 19 When the ester CH =C(Me)COO(CH CHO) H is reacted with the silane 61201101120 (HH2)Si(OMe)s in accordancewith the procedure of Example 13, the product CHz=C (Me) C O O(CH2OH20)100CH2OHOH2O (CH Si(OMe)z is obtained.

That which is claimed is:

1. The method of forming a molded article of improved strength whichcomprises mixing a polymerizable vinylic resin and a silane of theformula in which R is selected from the group consisting of H and themethyl radical, R is a divalent group composed of C, H and O, the latterbeing in a configuration selected from the group consisting of etherlinkages and OH groups, in R the ratio of C atoms to O atoms being notgreater than 3 to 1 and R being attached to both the CO0 and the R"groups through CO linkages, a has a value selected from the groupconsisting of 0 to 1, R" is an alkylene radical of from 1 to 4 inclusivecarbon atoms, and X is a hydrolyzable group, and impregnating a basemember with the mixture and curing the vinylic resin to form aconsolidated article.

2. The method of forming a molded article of improved strength asdefined in claim 1 which comprises mixing a polymerizable polyesterresin and a silane of the formula CHFC(CH )COO(CH Si(OCH impregnatingsiliceous fibers with the mixture and thereafter curing the polyesterresin to form a consolidated article.

3. The method of claim 2 in which the silane is present in amount offrom .05 to 5 percent based on the weight of the polyester resin.

References Cited UNITED STATES PATENTS 2,563,288 8/1951 Steinman 117-1262,649,396 8/1953 Witt et al. l17126X 2,922,806 1/1960 Merker 26044-8.22,934,464 4/1960 Hoffman et al. 117-126X 3,019,122 l/l962 Eilerman117l26X 3,258,477 6/1966 'Plueddemann et al. 260448.2

OTHER REFERENCES Adrianov, K. A., et al., Synthesis and Polymerizationof Organic Compounds with a Methacrylic Group, Izvest. Akad. NaukS.S.S.R., Otdel. Khim. Nauk 1957, pp. 459-65. (51 Chem. Abs. 15,457 f).

WILLIAM D. MARTIN, Primary Examiner D. COHEN, Assistant Examiner U.S.Cl. X.R. 117-161

